After adding Hibernate and Spring capability to the project, and all the configuration files(web.xml, applicationContext.xml) being well configged, one problem should be taken attention to, though it is a piece of cake. Yep, just a piece of cake, but i missed it and problem happened.
Never forget to import the jar file which is named: struts2-spring-plugin-2.1.6.jar.
without this, "struts.xml" fails to load configuration, and throws exception.
